Rohm Co., Ltd.

Kri, Inc.

Hiroshi Mataki

Toshimi Fukui

Satoshi Uchida

Hajime Sakiyama

Katsuhiko Ikawa

The present invention provides an organic/inorganic composite containing an inorganic phase dispersed in an organic polymer, the inorganic phase comprises one or more metal atoms that are coordinated to at least one rare earth metal atom via oxygen. The composite contains at least 5 mass % of rare earth metal. This rare earth metal is dispersed in the inorganic phase.

Organic/inorganic composite

The present invention provides an organic/inorganic composite containing a rare earth metal or/and Period IV transition metal in which the aforementioned rare earth metal or/and Period IV transition metal is doped at a high concentration, and control of quenching and optical transparency are assured thereby; and an optical amplifier, a light control optical element, and luminescent device utilizing the same. The organic/inorganic composite containing a rare earth metal or/and Period IV transition metal is one in which at least one species of rare earth metal or/and Period IV transition metal is dispersed in an organic polymer, with the aforementioned composite containing an optically transparent organic polymer and an inorganic dispersion phase comprising: (1) a rare earth metal and (2) another element coordinated thereto via an oxygen atom(s).

The present invention provides an organic/inorganic composite containing a rare earth metal or/and Period IV transition metal in which the aforementioned rare earth metal or/and Period IV transition metal is doped at a high concentration, and control of quenching and optical transparency are assured thereby; and an optical amplifier, a light control optical element, and luminescent device utilizing the same. The organic/inorganic composite containing a rare earth metal or/and Period IV transition metal is one in which at least one species of rare earth metal or/and Period IV transition metal is dispersed in an organic polymer, with the aforementioned composite containing an optically transparent organic polymer and an inorganic dispersion phase comprising: (1) a rare earth metal and (2) another element coordinated thereto via an oxygen atom(s). The inorganic dispersion phase in which another metal coordinates to rare earth metal or/and Period IV transition metal via an oxygen atom(s) preferably has an average particle size ranging from 0.1 to 1000 nm. Preferably, the ratio of rare earth metal or/and Period IV transition metal when mathematically converted to solid content is 90 mass % or less of the total mass of the organic polymer and the rare earth metal dispersion phase.

A semiconductor laser includes an active layer having a light-emitting region of striped structure. A cladding layer is formed on the active layer. Another cladding layer is formed under the active layer. The active layer is interposed between the cladding layer and the another cladding layer. Facets are formed on both ends of a stripe of the light-emitting region in which a part of light emitted radiated, and the remaining light is reflected and amplified. The semiconductor laser includes a means for having a minimum value of a coherence in a range between 2 mW and 7 mW of output of a light radiated from one of the facets which is a light output, and for preventing a phenomenon in which the output is reduced in a range at most 25 mW in accordance with an increase of the current, varied by a variation of a current applied to the active layer.

Semiconductor laser and method for manufacturing the same

A method for selecting a semiconductor laser exhibiting a desired relaxation oscillation frequency, including the steps of: (a) finding a correlation between a visibility of interference fringes of laser light generated by a sampled semiconductor laser and a relaxation oscillation frequency of the sampled semiconductor laser; and (b) measuring a visibility of interference fringes of laser light generated by each of semiconductor lasers to be subjected to selection and finding a relaxation oscillation frequency of that laser from the visibility thus measured with use of the correlation. This method is capable selecting semiconductor lasers exhibiting optimal high speed response characteristics for optical communications with less cost, avoiding a decrease in productivity for such lasers, and contributing to mass productivity therefor.

Method for selecting a semiconductor laser

A method for selecting a semiconductor laser is provided which contributes to improved productivity of a highly reliable semiconductor laser of prolonged lifetime, and which includes the steps of: (a) measuring highest peak intensity, Ia, and next highest peak intensity, Ib, of an interference fringes pattern of laser radiation of each semiconductor laser using an interferometer to find a damping ratio of visibility of the interference fringes pattern, .gamma.=Ib/Ia; and (b) selecting a semiconductor exhibiting self-pulsation by selecting a semiconductor laser which emits laser radiation whose damping ratio of visibility, .gamma., is 0.5 or less.

Method for selecting a self pulsating semiconductor laser

A self-aligned type, high-power semiconductor laser is provided which exhibits multi-longitudinal mode oscillation in the low-power operation (at a light power output of, for example, 3 mW) through it is of a refractive index guiding structure capable of single transverse mode oscillation in up to the high-power operation. Specifically, the semiconductor laser is of an AlGaAs system and has a waveguide mechanism resulting from complex refractive index, and wherein a current-blocking layer is 2000 to 6000 .ANG. thick.

Growing community of inventors

Kyoto, Japan

Hiroshi Mataki